Field of the Invention
The present invention relates to a toner transport mechanism used in an electrophotographic image forming apparatus.
Description of the Related Art
Image forming apparatuses, such as copiers, printers and facsimile machines, which form an image on recording material using an electrophotographic system may adopt a configuration in which toner such as untransferred toner having been generated in an image forming process and having become unnecessary without being transferred onto the recording material is transported to and stored in a recovery container. While transportation of unnecessary toner generally involves rotating a transporting member such as a screw or a spring installed on a transport path to transport the unnecessary toner to the recovery container, toner leakage sometimes occurs due to damage, an assembly error, or the like of the transporting member preventing the toner from being normally transported. Therefore, it is necessary to detect whether the transporting member is operating normally in order to prevent problems such as toner leakage from occurring. Meanwhile, problems occur in which toner accumulates on the transport path and toner clogging causes transportation failure, damage to parts, and the like despite the transporting member operating normally. In consideration thereof, mainly in order to manage a state of toner inside a recovery container, measures are taken which involve providing a flag member and a sensor on a downstream side on a toner transport path to detect a toner amount, as described in Japanese Patent Application Laid-open No. 2017-21123.